1. Field of the Invention
The present invention relates to a method of producing an N-hydroxycarbamate compound. The N-hydroxycarbamate compound is useful as a raw material for synthesizing medicines and pesticides.
2. Description of Related Art
As a conventional synthesizing method for an N-hydroxycarbamate compound, it is known to react hydroxylamine with a chloroformic acid ester. For example, German Patent No. 3,245,503 discloses a method of synthesizing (N-hydroxy) butyl carbamate by reacting hydroxylamine with butyl chloroformate.
Also, Org. Prep. and Procedures International, 19(1), 75(1987) discloses a method of synthesizing (N-methoxy-N-methyl)ethylcarbamate by preparing (N-hydroxy)ethylcarbamate from ethyl chloroformate and hydroxylamine hydrochloride and then methylating (N-hydroxy)ethylcarbamate with a methylating agent, in accordance with the reactions [A] and [B]: ##STR1##
As the above-mentioned reference discloses, (N-methoxy-N-methyl)ethylcarbamate can be converted to an alkoxyalkylamine by a hydrolysis and decarboxylation reaction procedure in which (N-methoxy-N-methyl)ethylcarbamate is mixed with an acid and the mixture is heated. The alkoxyalkylamine is useful as an intermediate for pesticides. The preparation of the alkoxyalkylamine is carried out in accordance with the reaction [C]: ##STR2##
Nevertheless, the above-mentioned prior art method is disadvantageous in that the chloroformic acid ester used in this method is usually produced from phosgene, which is a strong toxicant, and ethyl alcohol in accordance with the reaction [D]: ##STR3## Accordingly, a new method in which no strongly toxic phosgene is used is demanded to provide the N-hydroxycarbamate.
Also, the chloroformic acid ester per se has a strong toxity and corrosiveness and thus must be carefully handled, and reacted in a specific reactor having a high resistance to corrosion, and is expensive as an industrial material.
Therefore, the conventional method of producing N-hydroxycarbamate is not satisfactory for industrial utilization.